It is known in the art that automated systems have been developed for use in telecommunications applications wherein the automated systems will initiate or transfer a telephone call to a line which is expected to be answered. Many telephone networks or switches have a drawback in that they do not provide a positive indication to the calling system whether or when the telephone call has been answered. As those in the art can readily appreciate, if the automated system can detect the presence of voice in a telephone signal, such detection can be used to indicate whether or not a telephone call has been answered and, in response, the automated system can take appropriate action.
Thus, there is need in the art for method and apparatus for detecting whether a telephone signal received, for example, by an automated telephony system is produced by a voice.